Nonlinear control design of anti-lock braking systems with assistance of active suspension

With the utilisation of backstepping control design schemes, a nonlinear anti-lock braking system (ABS) is applied to a quarter-car model, assisted by active suspension. An ABS must be able to release the wheel-locking situation while assisting the vehicle to stop in the shortest possible distance. Although the braking distance can be reduced by the control torque from disk/drum brakes, the braking time and distance could be further improved if the normal force generated from active suspension systems is considered simultaneously. As a result, the integration of the ABS and the active suspension system would indeed enable further enhancement of the system performance resulting in a reduction of braking time and stopping distance. Some comparative simulations are given to illustrate the excellent performance of the proposed integrated ABS.